CHAP. XXII.] THE FLORA OF NEW ZEALAND. 



465 



able to receive immigrants from the former, at a later period, 

 and in a more or less fragmentary manner. 



If we examine the geological map of Australia (given in 

 Stanford's Compendium of Geography and Travel, volume 

 " Australasia "), we shall see good reason to conclude that the 

 eastern and the western divisions of the country first existed as 

 separate islands, and only became united at a comparatively 

 recent epoch. This is indicated by an enormous stretch of 

 Cretaceous and Tertiary formations extending from the Gulf of 

 Carpentaria completely across the continent to the mouth of the 

 Murray River. During the Cretaceous period, therefore, and 

 probably throughout a considerable portion of the Tertiary 

 epoch, ^ there must have been a wide arm of the sea occupying 

 this area, dividing the great mass of land on the west — the true 

 seat and origin of the typical Australian flora — from a long but 

 narrow belt of land on the east, indicated by the continuous 

 mass of Secondary and Palseozoic formations already referred to 

 which extend uninterruptedly from Tasmania to Cape York. 

 Whether this formed one continuous land, or was broken up 

 into islands, cannot be positively determined ; but the fact 

 that no marine Tertiary beds occur in the whole of this area, 

 renders it probable that it was almost, if not quite, continuous, 

 and that it not improbably extended across to what is now 

 New Guinea. At this epoch, then (as shown in the accom- 

 panying map), Australia would consist of a very large and 

 fertile Avestern island, almost or quite extra-tropical, and ex- 

 tending from the Silurian rocks of the Flinders range in South 

 Australia, to about 150 miles west of the present west coast, 

 and southward to about 850 miles south of the Great Australian 

 Bight. To the east of this, at a distance of from 250 to 400 

 miles, extended in a north and south direction a long but 



1 From an examination of the fossil corals of the South-west of Victoria, 

 Professor P. M. Duncan concludes — '^that, at the time of the formation of 

 these deposits the central area of Australia w^as occupied by sea, having 

 open w^ater to the north, with reefs in the neighbourhood of Java." The 

 age of these fossils is not known, but as almost all are extinct species, and 

 some are almost identical with European Pliocene and Miocene species 

 they are supposed to belong to a corresponding period. {Journal of Geol. 

 Soc, 1870.) 



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